The label is the law. Read your product's label before you mix or apply; the rates here come from the labels listed under Sources.
- Active ingredient
- Bifenthrin (CAS 82657-04-3)
- Chemical class
- Synthetic pyrethroid: a human-made version of the pyrethrins that come from chrysanthemum flowers.[1]
- Mode of action
- IRAC Group 3A: Sodium channel modulators (nerve action)[3]
- Signal word
- Bifenthrin TC (Bifen I/T): Caution[2]
How it works
Bifenthrin interferes with insects' nervous systems when they eat or touch it, and it is more toxic to insects than to people because insects have lower body temperatures and smaller bodies.[1]
It is in IRAC Group 3A, the sodium channel modulators, alongside deltamethrin, permethrin and the pyrethrins; switching to a product with a different group number is how resistance is slowed.[3]
Mixing it right
The label's formula for strength is 7.9 times the fluid ounces of Bifen I/T, divided by 128 times the gallons of finished spray, which gives the percent active ingredient: 0.33 fl oz per gallon is 0.02% and 1.0 fl oz per gallon is 0.06%.[2]
The label says not to use household utensils to measure it, and to repeat applications only when insects return, no more than once every 7 days.[2]
2026 label restrictions
The September 2026 label, revised under EPA's registration review, adds that applications must not be made during rain, must not run off, and must not be made when wind speed is greater than 15 mph; spot treatments must not exceed 2 square feet, and driveways, sidewalks and patios may only be spot or crack-and-crevice treated.[2]
Where it is used
Bifen I/T is labeled for perimeter and outside-surface sprays, indoor crack-and-crevice and spot treatments, lawns, ornamentals, mosquito control, livestock and poultry housing, and pre- and post-construction subterranean termite treatment by licensed applicators.[2]
Outdoors, residential sprays are limited to spot and crack-and-crevice treatment except for soil, lawns and other vegetation, a perimeter band no more than 7 feet wide from the base of the house, eaves and other surfaces protected from rain, a one-inch band around doors and windows, and walls up to 2 feet high where they rise above pavement.[2]
Products and registrations
| Product | Registrant | EPA Reg. No. | Active % | Formulation | Signal word |
|---|---|---|---|---|---|
| Bifenthrin TC (Bifen I/T)[2] | Control Solutions, Inc. | 53883-118 | 7.9% | concentrate (2/3 lb active per gallon) | Caution |
Label rates
| Product | Use | Pests | Rate |
|---|---|---|---|
| Bifenthrin TC (Bifen I/T) | Outside surfaces of buildings and perimeter band | Ants, spiders, roaches, earwigs, millipedes, ticks and other listed outdoor pests | 0.33–1.0 fl oz per gal of water[2] 0.02% to 0.06%, and no more than 0.33–1.0 fl oz per 1,000 sq ft. At homes the label's residential restrictions cap the perimeter band at 7 ft wide from the base of the house (an older section of the same label still says 6–10 ft); on walls above a driveway or sidewalk, spray no higher than 2 ft. |
| Bifenthrin TC (Bifen I/T) | Indoors: crack and crevice, spot, low-pressure spray | Ants, bed bugs (not as sole protection), cockroaches, fleas, spiders and other listed indoor pests | 0.33–1.0 fl oz per gal of water[2] Not a broadcast or space spray indoors; repeat no more than once every 7 days. |
| Bifenthrin TC (Bifen I/T) | Lawns (broadcast) | Armyworms, cutworms, sod webworms (low end); ants, chinch bugs, fleas, ticks, mole crickets (high end) | 0.18–1.0 fl oz per 1,000 sq ft[2] Never more than 1.0 fl oz per 1,000 sq ft. |
| Bifenthrin TC (Bifen I/T) | Adult mosquito residual spray | Mosquitoes | 0.33–1.0 fl oz per gal of water, applied at 1 gal per 1,000 sq ft[2] At the 1.0 fl oz rate, no more than once every 4 weeks; not when wind exceeds 10 mph. |
| Bifenthrin TC (Bifen I/T) | Subterranean termite soil treatment (licensed applicators only) | Subterranean termites | 1.0 fl oz per gal of water (0.06% emulsion)[2] 4 gallons of emulsion per 10 linear feet per foot of depth. |
How to apply it, step by step
1. Protective gear
- Anyone mixing, loading or applying it must wear a long-sleeved shirt, long pants, socks, shoes and chemical-resistant gloves; once the product is diluted, waterproof gloves are enough.[2]
- In a space with no ventilation, also wear protective eyewear and a respirator: at minimum a NIOSH-approved half-mask respirator with organic-vapor cartridges and R or P filters.[2]
- Wash gear with detergent and hot water, separately from other laundry, and wash your hands before eating, drinking, smoking or using the toilet.[2]
2. Before you spray
- Indoors, cover food-processing surfaces and utensils (or wash them before reuse) and cover or remove any exposed food; when spraying overhead, cover the surfaces below with plastic sheeting.[2]
- Outdoors, spray in calm weather when no rain is forecast for the next 24 hours, keep it out of storm drains, gutters and ponds, and don't spray blooming plants or weeds while bees are visiting.[2]
- Don't spray water dilutions onto electrical conduits, motor housings, junction boxes, switch boxes or other electrical equipment.[2]
3. Mixing
- Put the needed water in the sprayer, add the Bifenthrin TC, close the sprayer and shake it, and mix only as much as you need for the job.[2]
- For pests in and around buildings the label uses 0.33 to 1.0 fl oz per gallon of water (0.02% to 0.06%); for indoor residual treatments it uses 0.5 to 1 fl oz per gallon, with the higher rate on painted and non-porous surfaces.[2]
4. Applying
- Indoors, use a coarse, low-pressure spray (25 psi or less), a crack-and-crevice or spot spray, or a paint brush where pests hide: baseboards, closets, corners, around pipes, doors and windows, and behind and under cabinets and appliances.[2]
- For bed bugs, treat cracks and crevices in bed frames, box springs and empty dressers, but never bed linens, pillows, mattresses or clothes; the label says it shouldn't be your only bed bug treatment.[2]
- For wasp and bee nests, spray the nest, its entrance and the area around it in late evening, when the insects are at rest.[2]
- For treatments in buildings, repeat only if pests come back, and no more than once every 7 days.[2]
5. After you spray
- Keep people and pets off treated surfaces until the spray has completely dried.[2]
- Rinse the sprayer over the treated area rather than near a drain, so rinse water doesn't run off to water.[2]
First aid
- If swallowed, call a poison control center or doctor right away; have the person sip a glass of water if they can swallow, and don't make them vomit unless told to.[2]
- On skin or clothing, take off the contaminated clothing and rinse the skin with plenty of water for 15 to 20 minutes; in the eyes, hold the eye open and rinse gently for 15 to 20 minutes, taking out contact lenses after the first 5 minutes.[2]
- If inhaled, move the person to fresh air and call 911 if they aren't breathing. Have the label with you when you call; it lists SafetyCall at (866) 897-8050 for emergency medical treatment information.[2]
Storage, spills and disposal
- Store it upright at room temperature, away from extreme heat or cold, and soak up spills with an absorbent such as sand, sawdust or earth.[2]
- Never pour leftover product, spray or rinse water down a drain or sewer; call your local solid waste agency for disposal options.[2]
- Triple-rinse a container of 5 gallons or less: empty it into the sprayer, fill it a quarter full of water, cap and shake for 10 seconds, pour the rinse water into the sprayer, and repeat twice more; then recycle it if you can, or puncture it and put it in a sanitary landfill.[2]
From the safety data sheet
- The concentrate is an off-white liquid with a mild odor and no flash point (it will not flash); if it is caught in a fire, it can give off toxic gases including hydrogen chloride and hydrogen fluoride.[4]
- Store it upright at room temperature, away from heat, open flame, food, feed and children, and avoid extreme temperatures.[4]
- Soak up spills with absorbent pads, vermiculite or clay granules, keep spills out of storm drains and wastewater, and seal the waste in a container for disposal.[4]
- Skin contact with bifenthrin can occasionally cause tingling, burning, numbness or a rash; these sensations are reversible and usually fade within 12 hours.[4]
- The concentrate is extremely toxic to fish and aquatic invertebrates; keep it away from ponds, including ornamental fish ponds, and don't let wash water reach water.[4]
Safety and environmental hazards
People
On skin it can cause tingling, itching, burning or numbness at the contact spot that usually fades within 48 hours, and breathing it can irritate the nose, throat and lungs. EPA classifies bifenthrin as a possible human carcinogen based on studies in mice; studies feeding it to rats did not show cancer.[1]
Pets
Pets exposed to bifenthrin may vomit or have diarrhea, drool, flick their paws, twitch their ears or become less active; veterinarians have also reported incoordination and tremors. The label says not to let people or pets touch treated surfaces until the spray has dried, and never to apply it to pets.[1][2]
Bees and pollinators
The label states bifenthrin is highly toxic to bees exposed to direct treatment or to residues on blooming crops or weeds, and NPIC rates it very highly toxic to bees. Do not spray plants in bloom or let spray drift onto them while bees are foraging.[2][1]
Fish and water
The label states it is extremely toxic to fish and aquatic invertebrates. Bifenthrin binds tightly to soil, so it is unlikely to reach groundwater, but soil carried off in runoff can carry it into surface water, and it can accumulate in fish.[2][1]
Common questions
- Is bifenthrin safe for pets once it dries?
- The label's rule is to keep people and pets off treated surfaces until the spray has dried and never to apply it to animals. Pets that are exposed can drool, vomit, flick their paws or twitch, so keep them away while it is wet.[2][1]
- Does bifenthrin cause cancer?
- EPA classifies bifenthrin as a possible human carcinogen, a rating based on mouse studies; rat feeding studies did not show cancer, and it did not cause birth defects in rats or rabbits.[1]
- Can I use bifenthrin for termites myself?
- No. The Bifen I/T label limits termiticide use to individuals or firms licensed by the state to apply termiticides.[2]
Sources
- National Pesticide Information Center, “Bifenthrin General Fact Sheet.” npic.orst.edu/factsheets/bifgen.html (accessed 2026-10-06)
- U.S. EPA Pesticide Product Label System, “Bifenthrin TC (alternate name Bifen I/T) label, EPA Reg. No. 53883-118 (EPA-stamped, Sept. 1, 2026).” www3.epa.gov/pesticides/chem_search/ppls/053883-00118-20260901.pdf (accessed 2026-10-06)
- Insecticide Resistance Action Committee, “IRAC Mode of Action Classification Scheme, Version 11.5 (Feb. 2026).” irac-online.org/documents/moa-classification/ (accessed 2026-10-06)
- Control Solutions, Inc., “Bifen I/T Safety Data Sheet (Control Solutions, Inc., dated November 9, 2012; copy hosted by the City of Sioux Falls).” www.siouxfalls.gov/files/assets/public/v/1/health/public-health/mosquitos/bifen-it-sds.pdf (accessed 2026-10-15)